Missing image constructor in lua

[CIB]

black = Color(0, 0, 0);

Error in file Polycode/Image.lua on line 22
bad argument #1 to 'Image' (string expected, got number)

Trying to use this constructor:

Image(int width, int height, int type = IMAGE_RGBA);

[ivansafrin]

Since Lua (or rather my class system) doesn't support multiple constructors, I've added static accessors to all the other constructors. So you can use Image.BlankImage() instead